A Black Powder Burn Rate Timer Schematic

Schematic and Parts List Page

Just a few additional details....R15 in the schematic is listed as 33K ohms, but it is not a critical value. Another 47K resistor would work fine. The stop watch I ended up using is called a Cronus Pro Survivor which I bought for $19.99 US. The $5 stop watch in the picture is a Synchrotimer X-1000.

Parts list from BG Micro

(2) SWT1023 - Lever Mini Switch.................$2.50
(1) BAT1016 - 4 "AA" Battery Holder..........$0.79
(2) CAP1019 - Electrolytic 1 uf/100Vdc.........$0.78
(1) REL1006 - 5/6V Dip Relay.......................$0.99
(1) ICSHC123 - 74HC123...............................$0.35
(1) ICSHC00 - 74HC00...................................$0.25
(1) ICSHC02 - 74HC02...................................$0.25

Parts list from Radio Shack

(1) 270-1808 - Project box...............................$2.98
(1) 276-170 - perforated proto board...............$2.98
(1) 276-1114 - silicon diode, 1Kv, 2.5A ..........$0.49
(1) 275-612 - toggle switch..............................$1.49
(1) 271-1347 - 1/4 watt 100K ohm res. 5 for...$0.49
(1) 271-1342 - 1/4 watt 47K ohm res. .. 5 for..$0.49
(1) 276-2058 - 2N4401 transistor....................$0.49
(4) -------- AA alkaline battery................$1.99

If you have any questions or comments, then.... E-mail me!